Design and optimization of a microfluidic-based inductor used as a multifunction-sensor

Abstract

A planar miniaturized inductor has been designed in order to realize some transduction functions linked to the presence of fluids. Its electrical behavior has been studied for two liquids: Galinstan (an alloy of GALium INdium STANum) and salted water. Their presence between metallic armatures modifies the inductance value at a nominal frequency, chosen at 2GHz. By using a FEM software, the spatial distributions of magnetic field and surface current density in the entire device have been modelized for six arbitrary positions of these liquids in inductor microchannels. The geometrical aspects of the device have been studied and their influence examined for each liquid. We show that the inductor performances are influenced by the spiral width variations and the inter-turn distances of the coil. Considering the device as a sensor, we have evaluated the variations of two parameters: inductance and quality factors, which can respectively attain 664% (for Galinstan) and 175% (for salted water) from their nominal values.

Performance Evaluation of Microfluidically Tunable Microwave Filters

“…In a prior study [17][18][19][20][21], we proposed two RF MEMS tunable devices that allow for the incorporation of a microfluidic channel with double-turn electrodes. It is thus necessary to be able to change either their central frequency or their passband or both at the same time.…”

“…It is in this scenario that we have positioned ourselves throughout this work in order to evaluate a new tuning feature for variable microwave filters. Indeed, in this work, we associate two microfluidic tunable devices in the same wafer: an inductor [17][18][19] and a capacitor [20,21]. The advantage of these tunable devices lies in their ability to operate at different frequency bands using the simplest possible structure.…”